1. Field
The present invention relates generally to the field of wireless communications, and more specifically to systems and methods for early determination of network support for Mobile IP.
2. Background
Recent advances in wireless communications and the rapid expansion of use of the Internet have greatly increased the demand for mobile computing. Code Division Multiple Access (CDMA) technology has played a critical role in meeting that demand.
CDMA is a digital Radio-Frequency (RF) technique defined in the Telecommunications Industry Association/Electronics Industries Association Interim Standard-95, referred to as “IS-95,” and entitled “MOBILE STATION-BASE STATION COMPATIBILITY STANDARD FOR DUAL-MODE WIDEBAND SPREAD SPECTRUM CELLULAR SYSTEM,” which was published in July 1993 and which is considered as an example of a system for application of various embodiments of the present invention.
CDMA communications devices assign a unique code to communications signals and spread those signals across a common spread-spectrum bandwidth. As long as the communications device has the correct code, it can successfully detect and select its signal from among other signals concurrently transmitted over the same bandwidth.
The increased reliability of mobile communications has led to a demand for remote wireless computing wherein a computing device, such as a laptop computer or palmtop computer, is remotely coupled to a computer network (e.g., the Internet) via the mobile telephone. Although IS-95 does not explicitly define the protocol(s) for such remote wireless computing, a number of standards exist that specify protocols and/or algorithms for such interfaces and applications. The Internet Protocol (IP) standard has been incorporated into many wireless communication devices. The standard Request For Comment No. 791 (RFC 791) entitled “INTERNET PROTOCOL DARPA INTERNET PROGRAM PROTOCOL SPECIFICATION,” published in September 1981, is a network layer protocol that accommodates packetization of data for transmission. The addressing and routing information is included in packet headers. The headers contain addresses that identify the sending and receiving devices. These addresses are used by routers within the network to select a path to relay each packet to its ultimate destination at the intended destination address.
Another well-known protocol in wireless communications is the Point-to-Point Protocol (PPP), used to control wireless communications access to a computer network (e.g., the Internet). The PPP protocol is described in Request For Comment 1661 (RFC 1661), entitled “THE POINT-TO-POINT PROTOCOL (PPP),” published in July 1994. The PPP protocol specifies standards for transporting data of point-to-point links including a technique for encapsulating multi-protocol data, a Link Control Protocol (LCP) to establish and configure a data link and Network Control Protocols (NCPs) to establish and configure network-layer protocols.
Another standard, designated IETF RFC 2002: entitled “IP MOBILITY SUPPORT FOR IPv4” commonly referred to as “Mobile IP,” provides communications standards, but does not address wireless aspects of mobile computing.
With the adoption of third generation (3G) standards for CDMA communication, telecommunication standards have been introduced for wireless network communication. The Telecommunication Standard designated as IS-835, entitled “CDMA 2000 WIRELESS NETWORK STANDARD,” published in June 2000, and the Telecommunication Standard designated as IS-835A, published in May 2001, mandate a certain communication protocol for use with 3G CDMA devices. These standards are referred to herein as “IS-835.”
There is an increasing demand for packetized data services over wireless communication systems. As traditional wireless communication systems are designed for voice communications, the extension to support data services introduces many challenges. Specifically, the deployment of the IP for mobile devices (i.e., Mobile IP) has a unique set of requirements and goals. Mobile IP is the standard for IPv4 specifically. Other methods of deploying IP on wireless networks may exist. Mobile IP deployment in a wireless communication system presents unique requirements and issues unlike problems faced in deploying IP in a non-mobile environment.
One issue with Mobile IP is the overall cost of connection time and air resources. Mobile IP registration is performed after packet network connectivity has been established. In wireless networks, air resources and connection time are costly resources, both to the provider and consumer. Problems exist in Mobile IP deployment in managing and conserving resources.
There is a need, therefore, for an efficient method for managing the resources in a wireless communication system implementing Mobile IP. Specifically, there is a need for a method of early termination or disconnect of a mobile device from a wireless network when that network does not support Mobile IP. Additionally, there is a need for a method of detecting during or prior to origination of communication that a network does not support Mobile IP.